PURPOSE: To obtain a method for removing impurities contained in crude naphthalene by suppressing the loss of the naphthalene therein or without the loss thereof with a high efficiency, i.e. a method for producing the purified naphthalene of high purity in high yield.
CONSTITUTION: Purified naphthalene is produced from crude naphthalene. In the process, the crude naphthalene or hydrogenated naphthalene prepared by carrying out the hydrogenating treatment of the crude naphthalene is subjected to the dehydrogenating treatment. Thereby, other impurity components can be decomposed and removed without losing the pure naphthalene component contained in the crude naphthalene and the purified naphthalene can be produced in high yield. Furthermore, since tetralin can be returned to the naphthalene by the dehydrogenation even if the production ratio of the tetralin is increased in a hydrogenating purification process, the hydrogenating conditions at a high hydrodesulfurization ratio and hydrodenitrogenation ratio can be selected. As a result, the purified naphthalene of high quality can be produced.
YAMAMOTO YOSHITAKA
KANDA NOBUYASU
YAMADA MITSUAKI
SUDA YASUHIRO
TANIMICHI JISAKU
OSAKA GAS CO LTD
MITSUI SHIPBUILDING ENG
Shinichi Ogawa (2 outside)